Sperm Impacts: Environmental Factors, Lifestyle, And Medications Affect Male Fertility
Highlights From The Conjoint Meeting Of The American Society For Reproductive Medicine And The Canadian Fertility And Andrology Society19 October 2005
Montreal, Quebec ? Researchers at the conjoint meeting of the American Society for Reproductive Medicine and the Canadian Fertility and Andrology Society today presented their work on the way different lifestyle choices, environmental factors, and medications can affect male fertility.
Researchers from Yale University School of Medicine and the University of Connecticut reported results of their review of male infertility patients seen over a 10 year period who had a history of anabolic steroid abuse. They found that not all patients who have a history of anabolic steroid abuse are infertile and that, for many, fertility returns after steroid use ceases. This recovery may require hormonal treatment, but can also happen spontaneously. The researchers examined the records of 15 patients with a clear history of self-administered steroid use and an average age of 33. Eleven of the 15 had the low testosterone levels and low levels of FSH and lutenizing hormone expected for steroid abusers; four with normal hormone levels had other causes contributing to their infertility. Nine of the 11 were azoospermic; they did not have any sperm in their ejaculates, while two had low sperm counts. Seven of the nine azoospermic patients resumed sperm production after they ceased steroid use; five of these required hormonal treatment; the other two resumed spermatogenesis spontaneously. ***
Scientists in Sao Paulo, Brazil have found a correlation between urban levels of air pollution and a decrease in the male-female sex ratio at birth for mice and humans. Birth registries were consulted for the number of babies born between January 2001 and December 2003 in the areas monitored for pollution. In the least polluted areas 51.7% of the babies born were male; in the most polluted areas the percentage of males born decreased to 50.7%. In a corresponding experimental study using mice, male mice were housed for the first four months of their life in either a filtered air-chamber or were exposed to unfiltered ambient air. After four months both groups were mated with female mice that had not been exposed to pollution. Males from the filtered air environment produced offspring with a 1.34 male/female ratio, while males that had been exposed to polluted air produced offspring with a 0.86 male/female ratio. In addition, spermatogenesis in the mice exposed to air pollution was negatively affected.
At the University at Buffalo, in Buffalo, NY, researchers have demonstrated that chronic exposure to nicotine and tobacco smoke results in a significant loss in the fertilizing capacity of sperm. The researchers examined whether the sperm of chronic tobacco smokers was defective in binding ton the human zona pellucida (the outer membrane of the egg). The sperm from 18 men who had each smoked more than 4 cigarettes a day for two or more years (average 15.6 years) was compared to the sperm of screened research donors (controls) in the Hemizona Assay (HZA). In this test, non-viable donor oocytes were halved, then one half of each egg was incubated with a smoker?s sperm, while the matching half was incubated with control sperm. After incubation, the egg halves were examined and the numbers of sperm tightly bound to the zona pellucida were counted and compared. Two thirds of the smokers failed the HZA; their fertilizing capacity was just 25% that of the donors. An index representing the relative amount of smoking that a subject had done in his life was calculated for each smoker by multiplying the number of cigarettes per day by number of years smoking. Of those with the lower index scores, 71% passed the HZA; only 18% of the heavier smokers passed.
Michigan scientists investigated whether there was a connection between metal levels in the blood and semen parameters of men who ate fish caught in the Great Lakes. They analyzed data from 144 study participants who had submitted blood for testing levels of 12 metals, semen for analysis, and questionnaire detailing their fish consumption history. Men with a history of any fish consumption in the preceding 12 months showed high levels of mercury in their blood. But this was not restricted to consumers of Great Lakes fish; high mercury levels were even more strongly associated with consumption of ocean fish. However no association was found between sperm concentration or motility and any metal.
Researchers at the National Institute for Child Health and Human Development and Walter Reed Army Medical Center found that regular use of ibuprofen, a non-steroidal anti-inflammatory drug (NSAID) does not affect semen parameters and clinical pregnancy rates in assisted reproductive technology patients. In the past, experiments in mice and cattle have shown that NSAIDs decrease the production of prostoglandins, components of seminal fluid, without affecting sperm counts or motility. Patients having semen analyses at the clinic completed a survey including questions on use of medication- daily use was considered to be regular use. Sixty-eight (6.3%) of 1082 patients were regular users of ibuprofen. When their semen parameters, use of ICSI, and clinical pregnancy rates for ART were compared to intermittent and non-users of ibuprofen, no differences emerged.
In a prospective controlled study using sperm from normal donors and four brands of vaginal lubricants (Pre-Seed?, FemGlide?, Replens?, Astroglide?) often recommended to fertility patients, researchers found that one brand does not cause a significant decrease in sperm motility or damage to chromatin integrity, while the others do. In the first experiment for motility, donor sperm were incubated for 30 minutes in medium free of lubricant and in medium containing 10% vaginal lubricant. Sperm motility was measured after incubation and ranged from 66% in the lubricant-free control medium to 2% in medium containing Astroglide?. The best performing lubricant in this experiment was Pre-Seed? with 64% motile sperm after incubation. In the second experiment to gauge chromatin damage caused by the lubricants, donor sperm were incubated in lubricant-free medium as a positive control , in medium containing 10% KY? as a negative control and in medium containing one of two lubricants, Pre-Seed? and FemGlide? . After four hours incubation the sperm were evaluated for damage to their genetic material and graded in accordance with the DNA fragmentation index. Pre-Seed? demonstrated the smallest increase in chromatin damage with a 7% increase over the control.
Researchers from Reproductive Biology Associates in Atlanta report that a high body mass index (BMI) in men correlates with reduced testosterone levels. Patients? heights and weights were recorded on the day their blood was drawn to test for reproductive hormones. Patients? BMIs were calculated and they were grouped into the published ranges for normal, overweight, and obese. Average testosterone levels were calculated for each group and it was discovered that overweight men have levels 24% lower than men of normal weight and obese men have levels 26% lower. Men with high BMI typically are found to have an abnormal semen analysis as well.
Peter Schlegel, MD, President of the Society for Male Reproduction and Urology remarked, ?These presentations reflect the wide range of factors that can affect a man?s fertility and show that men, like women, face many risks to their fertility that they can control. While some risks are beyond the individual?s ability to influence, we recommend that people do what they can to stay healthy and avoid choices, like smoking, that are known dangers to health and men?s fertility.?